The present invention relates to a lift truck and especially to a lift truck for raising, lowering and moving boats, and related methods.
For a number of reasons, including the shortage and high price of waterfront land, the need to store boats on land has increased. It has become common to store similarly sized boats, e.g., boats of 30-40 feet in length, in horizontal racks. The racks are made to retain boats side-by-side, bow in, stern out, one above the other.
It is also necessary to provide transport vehicles capable of transporting the boats between the water and the racks. One commonly used device is a large counter-balanced fork truck modified to support a boat. A fork truck with long forks will hold a boat from the stern of most any shape hull design by adjusting the spread of the forks. A fork lift truck is dependent upon the weight behind the forward wheels to counter the weight of the boat. Larger lifting capacity can be obtained by moving the counterbalance weight farther from the boat, and/or by increasing the weight of the counterbalance.
Increasing the fork lift capacity can create certain problems. That is, as capacity is increased, the overall weight and length of the fork lift is increased. Increased weight means higher cost for equipment, shipping, and handling. Also, thicker and costlier pathways for the lift truck are required. In addition, the aisles in the storage facilities must be widened in order to accommodate the increased truck length. Increased weight also reduces the stability of the truck as it travels, especially downhill.
In order to be able to pass beneath a boat, the lift arms must be swung so that a relatively large distance between the horizontal boat-gripping forks or rails is provided. It has been proposed to provide the lift arms with axes. However, it is difficult to achieve the substantial separation between the horizontal portions of the lift arms without making the vertical portions of the lift arms quite long. This increases the vertical height of the lift truck to the point where the ceiling of the storage facility may be damaged.